Kinetic oiliness testing machine



Oct. 20, 1959 e. L. NEELY KINETIC OILINESS TESTING MACHINE 5Sheets-Sheet 1 Filed May 20, 1958 INVENTOR. GEORGE L. NEELV BY Adm amATTORNEY Oct. 20, 195 9 s. NEELY KINETIC OILINESS TESTING MACHINE 3Sheets-Sheet 2 Filed'May 20, 1958 INVENTOR. GEOQGE L. NEELV A TTO/PNEV0a. 20, 1959 G. L. NEE LY KINETIC OILINESS TESTING MACHINE 5Sheets-Sheet 3 Filed May 20, 1958 INVENTOR. GEORGE L. NEELY Wait. 61%

ATTORNEY other embodiment of the United States Patent KINETIC OILINESSTESTING MACHINE George L. Neely, Berkeley, Calif. Application May 20,1958, Serial No. 736,555 13 Claims. (Cl. 73-10 This invention relates toa friction or wear testing machine and particularly to one which isadapted to test the oiliness of a lubricant under controlled conditionsof rubbing materials, speed, temperature, and pressure, and in a mannerthat avoids consideration of the effect of viscosity of the lubricant,and has for a principal objective an improved arrangement of parts thatwill place the load-varying weights below the heated rubbing surfacesand also will insure continuous rotation of the friction elements underall speed and load conditions.

It is an improvement over the devices of my earlier joint patent with E.E. Edwards, No. 2,020,565, dated November 25, 1935, entitled FrictionTesting Machine, and the disclosure of that patent is incorporatedherein by reference. Essentially, the earlier arrangement consisted of avertical frame, at the lower end of which was a horizontal, variablyrotatable annular metal friction element or plate having two upstandingnarrow tracks concentric with the axis of rotation of the frictionelement. Means were provided for heating the friction element and thelubricant covering the tracks. A stationary vertical solid column orspindle extended upwardly through the annular plate and was providedwith a bearing for an upper circular plate having three downwardlyextending pivot bearings. Between each of the pivot bearings and the twoupstanding concentric tracks on the lower plate was a downwardly concavefriction button whose lower rim rested flat on the tracks and wasrotated by the unbalanced torque induced by the friction between thecircular rim and the rotating track surfaces.

In the previous arrangements of Patent 2,020,565, adjustments in weightor load on the upper annular plate and friction buttons, to vary theforce exerted by the buttons through the lubricant film against thetracks, were made by manually placing separate metal disc weights in apile on top of the upper plate. In one embodiment the torque or drag ofthe buttons due to the frictional contact with the lower rotating trackwas transmitted upwardly through a central frame, loosely pinned or,keyed to the upper plate, to be resisted by a radial leaf spring actingagainst a stationary outer column. In the previous arrangements, theupper plate, carrying the friction buttons, was positively rotated, andthe lower track was supported in a lower bearing and also was restrainedfrom rotation by a radial leaf spring. In both arrangements, however,the loading weights were above the friction buttons and the mountingmeans therefor, and were also in the heated zone above the lubricant.Under conditions of lubricant testing involving high temperatures 400 to800 F., it was diflicult to make changes in weights without protectivegloves and awkward weight-handling equipment.

In addition, to change or to clean friction buttons or the platecarrying the concentric tracks on which they rubbed, it was necessary topractically dismantle the entire machine, which was time-consuming.Also, and par- 2,909,056 Patented Oct. 20, 1950 2 ticularly in thefirst-named embodiment described above, the least misalignment of thecentral bearing for the upper annular plate carrying the frictionbuttons would cause the superposed pile of weights to wobbleand sway andresulted in uneven weight distribution on the buttons and indication ofthe machine.

The present invention has been developed and demonstrated to avoid thedifficulties just enumerated, and, in addition, to be much moreversatile in the ranges of loads that may be imposed, as it is adaptedto 'utilize weights that are separately controllable and mounted belowthe operating surfaces, away from the heated and vaporized lubricantzones. In addition, means have been provided for variably andcontrollably resisting the torque produced by the drag of the frictionbuttons on the tracks, particularly at low relative speeds of track andbutton rotation. Furthermore, a greatly simplified means has beenprovided for insuring individual rotation of the concave frictionbuttons around their individual axes, as will be further apparent below.

It is an object of this invention to provide a simplified arrangement ofa kinetic oiliness testing machine, to render it more sensitive andreadily controlled, and also to facilitate assembly and disassembly ofthe friction elements as is frequently required for cleaning whendifferent lubricants are tested in succession.

Another object is to provide a kinetic oiliness testing machine in whichthe friction elements are enclosed to be usable in a controlled gasatmosphere, and with provisions for venting the enclosure to remove gasor vaporized lubricant to an exhaust system. 7 v These and other objectsand advantages will be further apparent from the following descriptionand the attached drawings, which form a part of this specification andillustrate a preferred embodiment of the invention.

In the drawing,

Figure 1 is a vertical sectional view of the principal parts of theimproved device in their assembled and operative relations.

Figure 2 is a plan view on 'line 2-2 of Figure 1, showing thesubassembly of the load imposing head resting on the friction buttons inplace on the annular track, with the improved button rotation-inducingmeans.

Figure 3 is a vertical sectional view on line 33 of Figuire 2 showingthe relation of the buttons, track and lubricant-retaining cup. 7

Figure 4 is a vertical sectional view of an alternative arrangement ofa' friction button body with a rim of different material securedthereto.

Figure 5 is a horizontal sectional view on line 5-5 of Figure 1,illustrating a preferred arrangement ofthe uppermost of a plurality ofweight-imposing and weightreleasing means for the rod which extendsdownwardly from the load-carrying head.

Referring to the drawings and particularly to Figure 1, referencenumeral 10 designates a vertical hollow metal support column projectingupwardly through a horizontal plate 11, which forms the top of a housingfor the drive mechanism and loading weight accumulating means of themachine. At one side of column 10 below plate 11 is a conventional wormgear housing 12, in which are upper and lower bearings 13 for a verticalhollow shaft 14 to which is secured a worm gear 15. At one side of gear15 is a horizontal shaft 16, adapted to be rotated by a variable speeddrive; mechanism generally designated 17, with an appropriate wormengaging worm gear 15. Alternatively, helical or spur gear reductionscould be used for this purpose. This outer end 18 of shaft 16 isprovided with a speed indicator connector 19, having a shaft 20 leadingto a conventional speed indicator of any desired type, to indicate therate of rotation of shaft 16,

. 3 and more particularly that of vertical shaft 14 and its associatedfriction elements The top of vertical hollow shaft 14 projects upwardlythrough anoutwardlydiverging cne21, which forms the floor of a heatingchamber, and is right-hand threaded at 22 toja circular base plate 23 onwhich rests a frustoconical metal cup 24, having a central bore 25aligned with the bore of hollow shaft 14. Cup 24 is also provided withan outwardly and downwardly tapering skirt 26 extending into an, annularlubricant overflow trough 27, fromwhich excess lubricant may beconducted through conduit .28 to any suitable disposal means. a Anannular electric heating element 29 surrounds the lower outer face ofbase plate 23 to heat the friction elements and the lubricant beingtested. Element 29 is supplied with electric current from any suitablesource under the control of conventional means responsive to athermocouple element 30, which is slidably and rotatably mounted on ahorizontal rod 31 to be selectively immersed in lubricant inside of afrusto-conical cup 24. In Figure 1, the thermocouple element is shown inits retracted or withdrawn position, for convenience of illustration. Atone side of support column there is positioned a dripfeed oiler 32 withan outlet conduit 33 to supply lubricant to the friction, elements incup 24, which will be described in further detail below.

, :Desirably, the heatingchamber formed by cone 21 and thefrusto-conical cup 24 with its associated friction elements are enclosedby a vertically hinged metal shield generally designated 34, providedwith a transparent viewing window 35, and an electric light (not shown)so that the operation ofthe friction elements may be observed. Underconditions of high temperature operation, sufiicient lubricant may bevaporized, to cause objectionable fumes, which are exhausted from thehousing through ports 36 and the space 37 within hollow column 10 by asuitable blower exhauster. Ports 38 below the heating chamber admitcooling air from the housing below plate 11 and serve to cool shaft 14and its gears. This is also vented through ports 39 to space 37. Thereduced pressure in space 37 rnay be controlled by butterfly valve 40 atthe top of column 10.

Resting on the upper face of cup 24 and keyed to it so asto be. rotatedby hollow shaft 14 is a circular plate or friction element 41, having anupstanding inner track 42 and an upstanding outer track 43, of thepredetermined material, e.g., cast iron, bronze, steel, or the like,whose frictional or wear properties are desired to be investigated undercontrolled conditions in connection with a specific lubricant. Referencemay be made to my earlier Patent No. 2,020,565 for a detailed discussionof the characteristics and graphic layout of these tracks and the threefriction buttons generally designated 44 which co-operate withthem. Eachbutton is adapted to rotate about a downwardly extending pin 45 securedin loading head 46, spaced equally around a circle which lies betweentracks 42 and 43 as shown. Desirably, each button has a downwardlyextending hardened steel bearing cup 47 having a 120 concave seat for ananti-friction element such as a miniature ball bearing or, as in thiscase, a polished steel, Carboloy, or synthetic sapphire ball 48. Toretain the ball in place, the bottom of pin 45 also has a 120 cancaveseat of hardened steel. It is advantageous to have the center of theball 48 substantially in the plane of contact of tracks 42 and 43 andbuttons 44, as shown in Figure 3.

For this disclosure, and referring specifically to Figures 2 and 3, itis believed adequate to state that the diameters of the tracks 42 and 43of the diameter of the button 44 should be such that the four coplanarareas of contact between each button and the two tracks are equallyloaded, of substantially the same area, and well separated to facilitatea plane contact and proper rmafio 0 l buttons. Following is a table ofactual dimensions which have been found to be satisfactory.

Inches Outside diameter inner track 42 2.990 Inside diameter inner track42 2.882 Outside diameter outer track 43 4.000 Inside diameter outertrack 43 3.875 Outside diameter button rim 44 1.250 lnsidediameterbutton rim -44 1.125 Diameter of circle for pins 45 3.250

The center of loading head 46 (Figure 3) is provided with a cylindricalrecess 49 for an anti-friction bearing 50, preferably a self-aligningball bearing, the latter being supported in an appropriate groove Slatthe upper end of the inner hollow boss 52 of the frusto-conical cup 24.The inner face of recess 49 is smoothly finished so that bearing 50 willfreely assume a position in the recess at such a point that loading head46 is merely aligned to be coaxial with friction element 41 and cup 24and will not transmit any appreciable upward or downward force to cup.24. Extending upwardly around recess 49 of loading head 46 is acircular rim 53 on which is accurately centered a cap 54 provided with acentral bore 55, from one side of which is a transverse slot 56extending to the periphery of the cap. A hollow thimble 57 is adapted toseat in bore 55 and to support the outwardly beveled head of a loadingrod 58 which extends freely downwardly throughout the bore 25 of cup 24and also throughout and. below thebore of shaft 14. Sufiicicnt travel isprovid'edfor rod 58 so that when it is lifted slightly, thimble 57 maybe lifted from its seat in bore 55 and cap 54 may be moved sideways outof engagement with the rim 53 of loading head. 46, while thimble 57remains in place at the upper end of the rod. This will permit the.loading head 46, friction buttons 44, and friction element 41v to beremoved from cup 24, or if desired, the entire lubricant cup 24 and itscontents removed from base plate 23 for cleaning, inspection, orreplacement.

Below gear housing12 there are provided a plurality of verticallysuperposed weight control means (Figure 5) of identical construction andconstituting a graded series of weights which may be selectively coupledto rod 58 or detached therefrom, as will now be described. A generallysquare 'sheet metal frame 59 extends downwardly belowhousing 12 and, atthe level where each weight is to be supported, is provided with aweight-lifting frame 60, each pivoted at 61 to a horizontal rod 62 andhaving an outwardly extending handle 63, the latter projecting throughan inverted J-slot 64 in the outer corner of frame 59. ,An aperturedplate 65 is placed in each lifting frame 60 and supports the outwardlybeveled upper end of hollow sleeve 66 secured to each weight 67. Withineach sleeve 66 is an internal flange 68 which is adapted selectively torest upon a tapered sleeve 69 pinned to loading rod 58, when thatlifting frame handle 63 is lowered to the bottom of its inverted J-slot.This transmits the downward force of each weight to the loading rod 58.To raise the weight 67 from the rod 58, the handle .63 is lifted andmoved sideways into the laterally offset portion of the slot, as shownin Figure 1, thus lifting the weight 67 and disengaging flange 68 fromthe sleeve 66 of loading rod 58.v By appropriate selection ofcombinations of weights 67 controlled by the several superposed weightcontrol means, the loading rod 58 will exert the desired downward forceupon head 46 and, through .pins 45 and ball bearings 48, upon buttons44, to the lubricant on friction element 41. Desirably, a door 70 isprovided at one side of frame 59 to provide access to weights 67 and rod58. I

Referring now. to Figure 1, there will be described the torque orfriction drag, indicating means at the top of the machine, aligned withand above the friction element, buttons, andloading head just discussed.The support for these means comprises a. pair of brackets 71 and '72extending transversely from the vertical support column tion of shaft74."

'10, and each provided with an anti-friction'bearing 73 for a rotatablehollow shaft 74. The lower end of the shaft has a left-hand thread 75for a collar 76, to which is pivoted at 77 a forked or bifurcated arm78, the outer end 79 of which is selectively movable vertically aboutpivot 77. The outer end 79 of arm 78 is also bifurcated and is adaptedto be dropped downwardly to straddle the squared portion 80 of loadinghead 46 (Figure 2) and to transmit torque from head 46 to shaft 74. Whencollar 76 is loosened and rotated to lift arm 78, sufi'icient verticalclearance is provided above head 46 and cap 54 to disengage loading rod'58 (after the weights 67 have been lifted out of engagement with thatrod) by the procedure given above, so that the friction element andbuttons, or cup 24 and its entire contents, may be taken out of themachine for cleaning, inspection or replacement.

Above the lower bracket 72, and secured between the stationary bracketand shaft 74, is a conventional movable vane-type adjustable oil-filleddashpot generallydesignated 81 for absorbing oscillations of shaft 74due to varying friction conditions in the rubbing surfaces to which itis selectively connected as just described. The details of this dashpotform no part of this invention, and, as such devices are Well known inmeasuring instrurnents, needs no description herein.

Above the upper bracket 71 is mounted -a spring support bracket 82 towhich the outer ends of two substantially identical spiral steel springs83 and 84 are secured. The inner end of the lower spring 84 is securedat 85 to the hollow shaft 74. The inner end of upper spring 83 issecured to a bushing 86 journalled by an anti-friction bearing 87 to thetop of shaft 74. A hollow indicating drum 88 is secured to the upper endof shaft 74 and encloses both springs 83 and 84, the drum being free tomove through the same degree of rotation as does shaft 74 under therestraint of spring 84 and dashpot 81.

Under conditions of light loads on the friction surfaces, the singlespring 84' is adequate to exert a resilient restraining force on shaft74 and keep its rotation from exceeding the circumference of drum 88.Angular move- 'ment of that drum is indicated by an appropriatelygraduated scale around its lower edge, as related to an indexing marker89 on the outer end of upper bracket 71.

When heavier loads or friction and lubrication conditions require, thesecond or upper spring 83 may be connected in parallel with spring 84,just discussed, by a spring restrained detent member 90 in the top ofdrum 88, which selectively engages the bushing 86 and the drum 88 andmakes both springs effective to resist rota- The operation of thearrangement just described is believed to be clearly apparent to oneskilled in this art from the foregoing description and the attacheddrawings. It has been found to give a much wider range of operatingconditions and more reproducible and accurate results than the devicesof my previously issued Patent 2,020,565. Generally, it will be foundthat the friction buttons 44 will be continuously rotated by therelative friction forces exerted upon them by the continuously rotatingtracks 42 and 43 on friction element 41. With the dimensions givenabove, it will be found that the track will make about three revolutionsfor each revolution of the friction buttons.

Under some circumstances, however, the buttons 44 may fail to rotate,due to slight imperfections or burrs at their edges, extreme loading, orother causes. In order to prevent the sliding and damage that would thenoccur, it is desirable to provide them with a concave groove 91 (Figures3 and 4) into which may be freely snapped or tightly secured anencircling helical wire spring 92 of such resiliency that its adjacentturns will be slightly spaced apart to form resilient loops as shown. Atone side of friction member 41, outside of tracks 42 and 43, at anappropriate radius, is placed a horizontally "pivoted pin 93, which maybe selectively stood upright,

as shown, or pivoted to lie horizontally. In its upstanding position,pin 93 will engage the outer edge of one or more passing loops of spring92 and thereby urge the button 44 on which it is mounted to rotationabout its bearing pin. The curvature of the circular spring and g theangularity of the adjacent wire loops will be found 95, as by shrinkingor pressing it into a circumferential groove 96, and retaining it by apin 97. This is particularly true if a hard and brittle material, suchas Carboloy, is to be used.

Although three circumferentially spaced rotatable buttons are'describedin this illustrative example, it will-be apparent that a greater orlesser number could be used so long as at least one is provided to bepositioned with its rim in contact with both tracks of the rotatingfriction element so as to be rotated thereby about its own centralbearing. This bearing is necessarily displaced radially from the axis ofrotation of the friction element, as will be apparent from Figure 1, sothat the frictional drag between the button and the tracks, in thepresence of the lubricant, will tend to impart a I measurable torque orangular rotation to the button potracks could be imposed by fewer orsmaller weights than if more were employed, as in this example.

In conclusion, it will be understoodthat, while a single example of thisinvention has been illustrated and described, numerous modifications andchanges could be made without departing from its essential features.Accordingly, all such changes that come 'Within the scope of theappended claims are intended to be embraced thereby.

I claim: 1. An oiliness testing machine comprising a rotating frictronelement provided with two annular tracks, lubricant supply means forsaid friction element and said tracks, means for contacting threeequally spaced, independently axially rotatable circular frictionbuttons on said tracks, said last-named means comprising a rotatablehead aligned with the axis of rotation of said friction element andhaving an axial bore, elongated means seated in said bore and extendingdownwardly below said rotating friction element, means for selectivelyadding and subtracting weights to said elongated means beneath saidfriction element to vary the contact pressure between said frictionbuttons and said tracks, means for indicating the torque imposed uponsaid head by said buttons, a frusto-conical cup surrounding saidfriction element, and a trough beneath the lower outer edge of said cupto receive excess lubricant passing over the top and outer face of saidcup.

2. An oiliness testing machine according to claim 1 with the addition oftemperature responsive means adapted selectively to be positioned inlubricant retained inside of said cup and outside of said tracks.

3. A kinetic oiliness testing machine comprising a continuouslyrotatable friction element provided with two upwardly extending annulartracks, means for controllably rotating said element, a plurality offriction but tons, each having a downwardly directed rim, means 7iournalled on said, rotating element for rotatably positioning each ofsaid buttons with its rim in contact with both of said tracks at apredetermined distance from the axis of rotation of said element, aresilient helically coiled member encircling each of said buttons, andan upstanding pin on said element outside of said tracks adaptedsuccessively to engage the coils of said heli- .cal members to impartrotation to said buttons about their axes.

4. A friction button for a kinetic oiliness testing machine having arotatable friction element provided with annular tracks and a pincarried by said element adjacent the outermost track, said buttoncomprising a circular body portion having an axial bore for receiving abearing element, an outer rim extending from one face of said circularbody, to contact said tracks, and means providing a succession ofresilient loops surrounding said body and adapted to be engagedperiodically by said pin forwimparting rotation of said button about itsbearing element,

5. A friction button according to claim 4 in which said rim is of adifferent material than said body and is secured against relativerotation in a groove in one side of said body.

6. A friction button according to claim 4 in which said last-named meansis a helical spring removably mounted in a concave groove encirclingsaid body.

7. A friction button according to claim 6 in which said helical springcomprises a resilient metal wire under sufficient tension to retain itin said groove on said button.

8. A friction testing machine comprising a vertically journalled gearhaving a hollow shaft, variable speed means for rotating said gear, arotatable friction element removably mounted on the upper end of saidshaft, two circular tracks on said element, a removable head journalledat the top of said element, a plurality of concave friction buttons.journalled at equally spaced circumferential positions on said head,each button having a downwardly directed rim adapted to engage the topof said tracks, torque indicating means aligned with the upper end ofsaid hollow shaft, a coupler for selectively connecting said torqueindicator to said head, said coupler being retractable upwardly topermit removal of said friction element, a rod selectively engageable atits upw per end with said head, and extending downwardly throughout andbelow said hollow shaft, and means for selectively loading the lowerportion of said rod.

9. A friction testing machine according to claim 8with the addition of alubricant feed means for said tracks and said buttons, a heater for saidfriction element and the lubricant thereon, a housing'surrounding saidfriction element, head, buttons and coupler, and means for controllablywithdrawing gaseous materials from said housing.

10. An oiliness and friction testing machine comprising a frictionelement rotatable about a vertical axis and having concentric tracks onits upper surface, means for rotating said element, coaxial torqueindicating means above said element, at least onerconcave frictionbutton having a downward directed rim adapted to engage the top of saidtracks, said button being rotatable about a central bearing, means forimposing a downward force on said bearing and for positioning saidbutton with respect to said tracks, and horizontally pivoted meansconnecting said torque indicating means to said force imparting means,for transmitting the frictional drag between said button and said tracksto said torque indicating means.

11. Anoiliness and friction testing machine according to claim 10 inwhich said horizontally pivoted means are supported by said torqueindicating means and extend radially therefrom.

12. An oiliness and friction testing machine comprising a frame, afriction element rotatable about avvertical axis in said frame andhaving two concentric tracks, means for rotating said element, at leastone concave friction button having a downwardly directed rim adapted toengage the top of said tracks to be rotated thereby, said button havinga central bearing, means engaging said bearing for positioning it withrespect to said tracks and for imposing a downward force thereon,resilient torque opposing means axially aligned with said frictionelement, horizontally pivoted means connecting said last-named means andsaid bearing positioning means, the angular deflection of said pivotedmeans and said torque-opposing means with respect to said frame being anindication of the frictional drag between said button and said tracks.

, 13. An oiliness and friction testing machine comprising a'framc, afriction element rotatable about a vertical axis in said frame andhaving two concentric tracks, means for rotating said element, at leastone adjustably loaded concavefrictio'n button having a central bearingand a downwardly directed rim adapted to engage the top of said tracksto be rotated thereby about said bearing, a horizontally pivoted .arrnsupported in said frame and connected to said central bearing of saidbutton, torque opposing References Cited in the file of this patentUNITED STATES PATENTS Neely et al Nov. 12, 1 935 Mims Jan. 6, 1959

